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In this study, the gray box method has been used to model traffic accidents for the first time. This work examines the problem of estimating and identifying a single-input single-output state-space system. In this way, the state-space model was used, which has both a black box section (experimental data) and the parameters have been estimated by acquiring prior knowledge (white box). First, the state-space of the desired system is formed, and the algorithm for estimating the parameters and their convergence and the state vector estimation algorithm are written. In comparison, the system changes from nonlinear to linear. The parameters and prior knowledge are entered from the system. Finally, by implementing the presented method on the data related to the factors affecting accidents in Qazvin (Iran), the accuracy of the presented materials is investigated. The error output shows that initially, the error increased slightly, but then it shows a downward trend, and with the increase in the data, the error tends to zero (0.658). The results also show good fit and optimal accuracy of the model in less processing time.

Assessing the structural health of operational wind turbines is crucial, given their exposure to harsh environments and the resultant impact on longevity and performance. However, this is hindered by the lack of data in commercial machines and accurate models based on manufacturers’ proprietary design data. To overcome these challenges, this study focuses on using Gaussian Process Regression (GPR) to evaluate the loads in wind turbines using a hybrid approach. The methodology involves constructing a hybrid database of aero-servo-elastic simulations, integrating publicly available wind turbine models, tools and Supervisory Control and Data Acquisition (SCADA) measurement data. Then, constructing GPR models with hybrid data, the prediction is validated against the hybrid and SCADA measurements. The results, derived from a year of SCADA data, demonstrate the GPR model’s effectiveness in interpreting and predicting turbine performance metrics. The findings of this study underscore the potential of GPR for the health and reliability assessment and management of wind turbine systems.

Abstract Channel models for outdoor wireless systems usually assume two-dimensional (2D) random scattering media. In the practical outdoor wireless channels, the impact of the wave propagation in the third-dimension is definitely important; especially when the communication system efficiently exploits potentials of multiple antennas. In this paper, we propose a new model for multiple-input multiple-output (MIMO) multicarrier propagation channels in a three-dimensional (3D) environment. Specifically, the proposed model describes the cross-correlation function (CCF) between two subchannels of an outdoor MIMO channel employing directional antennas and in the presence of nonisotropic wave propagation in 3D space. The derived CCF consists of some correlation terms. Each correlation term is in the form of a linear series expansion of averaged Bessel functions of the first kind with different orders. In practice, each correlation term has a limited number of Bessel components. Our numerical evaluations show the impact of different parameters of the propagation environment as well as the employed antennas on the resulting CCF. Using the proposed CCF, we also establish simple formulas to approximate the coherence time, the coherence bandwidth and the spatial coherence of such channels. The numerical curve fitting results fit to the empirical results reported in the channel modeling literature.

Background: Some studies indicate that more than 10% of pregnant women are affected by psychological problems. The current COVID-19 pandemic has increased mental health problems in more than half of pregnant women. The present study compared the effectiveness of virtual (VSIT) and semi-attendance Stress Inoculation Training (SIT) techniques on the improvement of the symptoms of anxiety, depression, and stress of pregnant women with psychological distress., Methods: This study was conducted on 96 pregnant women with psychological distress in a 2-arm parallel-group, randomized control trial between November 2020 and January 2022. The semi-attendance SIT received treatment for six sessions, sessions 1, 3 and 5 as individual face-to-face and sessions 2, 4 and 6 as virtual once a week for 60 min continuously [n = 48], and the virtual SIT received six sessions simultaneously once a week for 60 min (n = 48) in pregnant women of 14-32 weeks' gestation referred to two selected hospitals. The primary outcome of this study was BSI-18 [Brief Symptom Inventory] and NuPDQ-17 [Prenatal Distress Questionnaire]. The secondary outcomes were the PSS-14 [Cohen's General Perceived Stress Scale]. Both groups completed questionnaires measuring anxiety, depression, pregnancy-specific stress, and generally perceived stress questionnaires before and after the treatment., Results: The post-intervention results showed that the stress inoculation training technique in both VSIT and SIT interventions effectively reduced anxiety, depression, psychological distress, pregnancy-specific stress and general perceived stress [P < 0.01]. Also, the SIT interventions on decreasing anxiety [P < 0.001, η2 = 0.40], depression [P < 0.001, η2 = 0.52] and psychological distress [P < 0.001, η2 = 0.41] were more considerable than that of VSIT. However, There was no significant difference between SIT and VSIT intervention in terms of their effects on pregnancy-specific stress [P < 0.38, η2 = 0.01] and general stress [P < 0.42, η2 = 0.008]., Conclusion: The semi-attendance SIT group has been a more effective and practical model than the VSIT group, for reducing psychological distress. Therefore, semi-attendance SIT is recommended for pregnant women., (© 2023. The Author(s).)

Background and Aims: Previous studies have introduced insulin resistance (IR) as a major risk factor for poor cardiovascular diseases (CVDs) outcomes. Diet, body weight, and physical activity are three key pillars of lifestyle that can significantly impact the IR status. We aimed to assess the possible link between the empirical dietary index for IR (EDIR) and the empirical lifestyle index for IR (ELIR) with the risk of chronic heart disease (CHD) and CVDs., Methods and Results: This study was conducted on 4980 participants aged ≥30 years (follow-up rate: 99.85%). Dietary intake data was collected using a validated food frequency questionnaire. Cox proportional hazard regression was used to estimate the hazard ratio and 95% confidence intervals (HRs and 95% CIs) of CVDs and CHD across tertiles of EDIR and ELIR scores. In the final model, after adjusting for all potential confounding variables, participants in the highest tertile of EDIR had a higher risk of CVD (HR:1.36, 95%CI:1.03-1.80, P-trend = 0.016) and CHD (HR:1.36, 95% CI:1.01-1.83, P-trend = 0.023) compared to the lowest tertile. Also, participants with a higher score of ELIR had a higher risk of CVD (HR: 1.64, 95%CI:1.24-2.16, P-trend=<0.001) and CHD (HR: 1.72, 95%CI:1.28-2.32, P-trend=<0.001)., Conclusion: A greater adherence to the lifestyle and diet with a higher EDIR and ELIR may be associated with an increased risk of CVD and CHD outcomes in the adult population., Competing Interests: Declaration of competing interest The authors declared there is no conflict of interest., (Copyright © 2022 The Italian Diabetes Society, the Italian Society for the Study of Atherosclerosis, the Italian Society of Human Nutrition and the Department of Clinical Medicine and Surgery, Federico II University. Published by Elsevier B.V. All rights reserved.)

A novel hexagonal airlift flat plate (HAFP) photobioreactor was designed to improve microalgae growth rate and compared with traditional flat plate (TFP) photobioreactor. The computational fluid dynamics (CFD) simulation was used to determine hydrodynamic parameters and optimal aeration rate in the photobioreactors. Additionally, the capability of the HAFP photobioreactor to enhance microalgae based CO 2 bio-fixation and wastewater treatment were investigated. The results of CFD simulation indicated that the HAFP photobioreactor could improve hydrodynamic parameters of turbulence kinetic energy (TKE), average fluid velocity, dead zone (DZ), and water shear stress (WSS) up to 78 %, 41 %, 44 % and 40 %, respectively, under optimal aeration rate of 0.6 vvm. The proposed HAFP photobioreactor showed a drastic improvement in microalgae growth (up to 61 %). The maximum CO 2 removal of 53.8 % and bio-fixation of 0.85 g L -1 d -1 were achieved in the HAFP photobioreactor which were approximately 70 % more than that in the TFP photobioreactor. The results suggested that the HAFP photobioreactor could accelerate nutrients removal and achieve remarkably higher efficiencies of 91 %, 99 %, 97 % and 93 % of ammonia (NH 3 ), nitrate (NO 3 - ), phosphate (PO 4 3- ) and chemical oxygen demand (COD) within seven days of cultivation., (Copyright © 2021 Elsevier Ltd. All rights reserved.)

Quorum sensing signals regulate various functions within activated sludge processes such as formation of microbial aggregates. Disturbance of this signaling system, known as quorum quenching (QQ), provides opportunities for eliminating some problems related to biological wastewater treatment (e.g., biofouling and excess sludge production). However, it is poorly understood how and to what extent QQ systems can affect the microbial aggregation processes and the following floc formation. In particular, an in-depth structural characterization at the scale of microbial aggregate while considering nutrient conditions in the reactor is still largely disregarded. Here, we evaluated the QQ effects at the short-term time scale (i.e., after 4 h for the exogenous period and 19 h for exogenous/endogenous period), by combining advanced techniques for microbial characterization (flow cytometry, CARD-FISH, and confocal laser scanning microscopy) and conventional physical-chemical assessments. The results indicated that by implementing QQ agents (immobilized Acylase I enzyme in porous alginate beads) the abundance of single cells and suspended microbial aggregates in the supernatant did not show significant changes during the exogenous period. Conversely, at the end of the exogenous/endogenous period a significant increase of single prokaryotic cells, small and large microbial aggregates favored the growth of grazers, including free-living nanoflagellates and ciliates. Flocs became looser and thinner than those in the control reactor, thus affecting the sludge settling behavior. Inability of microbial community in degradation of soluble protein during the endogenous period confirmed that the QQ agents are likely to inhibit the secretion of protease enzyme within microbial communities of activated sludge., (Copyright © 2020 Elsevier Ltd. All rights reserved.)

The present study provided a comparison of two species of microalgae growth in dairy wastewater treatment plant effluents. In optimum conditions their operation to biomass production, lipid accumulation and fatty acids methyl ester composition so as to biodiesel production is studied. For the first time, the not sterilized effluents of dairy wastewater treatment plant was used as the culture mediums of native microalgae, Chlorella sorokiniana strain pa.91, and another one Chlorella vulgaris . They were cultured under 5 light intensity levels so as to find optimum conditions to observed high biomass and lipid production. At the optimum light intensity the composition of fatty acids methyl ester in their lipids was analyzed by GC-MS. The light intensity of 7500 Lux was obtained as the optimum for both microalgae to produce high biomass. The biomass productivity of C. sorokiniana pa.91 and C. vulgaris in preliminary treated effluent at this light intensity was obtained 0.233 and 0.214 g L -1  day -1 , respectively. This parameter in secondary treated effluent was achieved 0.185 and 0.166 g L -1  day -1 , respectively. Moreover, the highest lipid content of their biomass was observed at the light intensity of 2500 Lux. At this light intensity and at the preliminary effluent the maximum lipid content of C. sorokiniana pa.91 and C. vulgaris was observed 31% and 34%, respectively and at the secondary one it was obtained 35% and 36.67%, respectively. Based on the results, the fatty acids composition in the lipids of microalgae C. sorokiniana pa.91 and C. vulgaris cultured in both effluents had the high amount of cetane number which is really useful for high quality biodiesel production. Also, the other valuable properties which produce the high quality biodiesel were the obtained amounts of CFPP and CP which shown a high performance potential biodiesel even at low temperatures. This feature was obtained, on the grounds that the unsaturated fatty acid was obtained more than saturated fatty acid. The nutrients-rich media of dairy wastewater effluents were applicable to growth both microalgae and useful biomass production, lipid accumulation and fatty acids profiling. Furthermore, the compounds of fatty acids had the best conditions to biodiesel production especially in cold weather areas., Competing Interests: Conflict of interestThe authors declare that they have no competing interests., (© Springer Nature Switzerland AG 2020.)

Anaerobic digestion is one of the common methods of managing and stabilizing sludge. However, due to the limitations of the biological sludge hydrolysis stage, anaerobic decomposition is slow and requires a long time. This study evaluated the effects of thermal (80 °C) (TH-PRE) and a combination of thermal with the lysozyme enzyme (LTH-PRE) pretreatments on the enhancement of anaerobic activated sludge digestion. Response surface methodology was implemented to optimize enzyme pretreatment conditions (enzyme and mixed liquid suspended solids concentration). The results showed that both pretreatment methods increase soluble chemical oxygen demand (COD) and reduces total and volatile suspended solids (VSS), and phosphate concentration. The COD removal rate in LTH-PRE and TH-PRE was 95% and 81%, respectively. The value of VSS reduction in LTH-PRE and TH-PRE was 41% and 31%, more than the control operation, respectively. The biogas production in LTH-PRE and in TH-PRE also increased by 124% and 96%, respectively.

Treatment of wastewater by using of microalgae is a cost-effective system. Chlorella sorokiniana pa.91 and Chlorella vulgaris were studied in this research. Chlorella sorokiniana pa.91 was isolated from the dairy wastewater. In this study, treated wastewaters in preliminary and secondary treatment units of dairy wastewater treatment plant were used as medium. Maximum growth of two species of microalgae was examined in these two mediums, and also, nutrient removal was studied. The performance of two species of microalgae was studied on laboratory scale at different temperatures and light intensities. The best observed temperatures for Chlorella vulgaris and Chlorella sorokiniana pa.91 were 25 and 28 °C, respectively, and the best observed performance for them was obtained at 7500 lx. The values of specific growth rate and biomass productivity in effluent of preliminary treatment unit for Chlorella vulgaris were 0.331 day -1 and 0.214 g L -l  day -1 , respectively, and for Chlorella sorokiniana pa.91 were 0.375 day -1 and 0.233 g L -l  day -1 , respectively. Also, these parameters for Chlorella vulgaris in effluent of secondary treatment unit were determined 0.359 day -1 and 0.166 g L -l  day -1 , respectively, and for Chlorella sorokiniana pa.91 were obtained 0.422 day -1 and 0.185 g L -l  day -1 , respectively. The removal efficiency of nitrate, ammonia, phosphate, and chemical oxygen demand for Chlorella sorokiniana pa.91 and Chlorella vulgaris in both of effluents was more than 80%. Based on the results, effluent of treatment plants can be a suitable microalgae growth medium, and the microalgae can be used as effective post treatment system.

The Quorum Sensing (QS) system has attracted the interest of researchers as a cell-cell communication system. In activated sludge processes, the production of extracellular polymeric substances (EPS), biofilms and floc formation are regulated by the QS system. Hence, disruption of the QS system, called Quorum Quenching (QQ), could have a significant effect on the quality and quantity of excess sludge. In the present research, the quorum quenching bacteria, Rhodococcus sp. BH4 was used as a quorum quencher and was entrapped in an alginate structure (QQ beads). Three separate sequential batch reactors (SBR) were constructed and operated as a control reactor, a Low-QQ reactor (containing 150 QQ beads), and a High-QQ reactor (containing 600 QQ beads). Results indicated that the presence of QQ beads in the aeration reactor leads to a decrease in EPS content and mean floc particle size in the both Low-QQ and High-QQ reactors. The eukaryotic community was changed significantly so that the QS disruption caused an enhancement in microbial predation. The presence of QQ beads also led to a 16 and a 26% decrease in the Y obs coefficient within the Low-QQ and High-QQ reactors, respectively. Findings of this research revealed a new application of the QQ system in the activated sludge process, but additional studies are needed., (Copyright © 2018 Elsevier Ltd. All rights reserved.)